This something I did on Roadfly, I know everyone has lots of questions about the E90. I tried to compile as much rumored info as possible about what's been heard to happen and likely will happen. Hope you guys enjoy!

This is a collection of most of the info out there on the E90, please remember these are rumors and speculations given BMWs patterns with new models and ONLY SPECULATION, NOT 100% ACCURATE INFORMATION FOR THE E90. Hope this answers questions, enjoy!

BODYSTYLE:
The E90 will come in Sedan, Touring, Coupe, and Convertible body styles. The E90 will come first as a sedan and likely touring in mid 2005. with the touring, coupe, and convertible coming in late 2005 early 2006. Expect styling cues from the X3 and the flame surfacing of the Z4 to cross over to the E90, though this will be the most subdued of any of the Chris Bangle designs. The interior is rumored to have styling cues of the Z4's dash with a mix of the interior of the new E60 5er.
ENGINES:
The engine rumors are still rumors. Rumors range from for the first year or two of production keeping valvetronic versions of the 2.5L and 3.0L engines. Other rumors state that the E90 will have brand new engines at release as the Z4 is due for new I6 engines at the same point in 2005. It's said that a light weight aluminum V8 is in the works, likely the 4.5L Valvetronic V8 in the 745i and 545i. Horsepower is expected to get a good boost to keep BMW in line with its competition with the lower range E90 having 200HP to 230HP while the V8 will come in around 300HP. Other inline 6's are expected to fall between the V8 and smaller I6, likely around 250HP to 280HP. Turbos are apparently being considered though go against BMW's NA engine policy of recent years, so this is the most questioned engine as it was rumored to be coming to the E60 5er a few years back.
OPTIONS:
BMW will almost definitely make adaptive bi-xenons a low cost options if not standard. Interior-wise expect a Nav system with a possible optional IDrive. It seems BMW might leave Idrive as optional given its mixed reviews from the 7 and 5 and the fact that the 3er is more driver oriented than the higher echelon models. Tranmissions will come as a six speed manual, six speed steptronic and six speed SMG( or some next gen. iteration of the current SSG). Expect of course the sports, premium and cold weather packages to be available. My guess is the wheel size on the optional sports package will likely increase to 19 inch rims or some sort of 18inch M designed rim with a lip to add sportiness.

PERFORMANCE:
Expect the highest E90 engine model to likely run a 0 to 60 time in the mid to high 5 second range with the lower I6 models coming in at likely the mid 6 to 7 second range. Theres a very good chance that with the Inline 6's at least, BMW will keep 50:50 weight distribution.

M DIVISION:
It seems that we'll see an M version of almost every E90 bodystyle: Coupe, Convertible, and the reintroduction of the Sedan(a la E36 M3 Sedan). Power is believed to be from a all aluminum V8 with around 400HP but no word on a stable or likely 0 to 60 time.

PRICING:
Prices, like most cars and BMW's current path, will increase by around 5%. This can be a reliable bet because the highest E81 1er will come in loaded right around the base price of the current E46 325i. No word on specific model prices, especially with what seems to be a greater number of engines in the line up.